The objectives of this project are to identify and describe environmental and host determinants of cancer in areas at high risk of cancer through the use of analytical epidemiologic and biometric techniques, particularly case-control studies of specific cancers. Completed during the year were analyses of kidney cancer in Minnesota, where ethnic factors, cigarette smoking, and (among women) high relative weight were associated with renal adenocarcinoma, and where cigarette smoking and long-term intake of certain analgesics were found to be risk factors for renal pelvis cancer. Interviewing was completed for case-control studies of respiratory cancer in New Jersey and coastal Texas; bladder cancer in rural New England; and esophageal cancer in coastal South Carolina. Data are currently being prepared for analysis, but initial results of the lung cancer investigations reveal elevated risks among several occupational groups, including shipyard workers in New Jersey and construction workers in Louisiana and Texas. Smoking of hand-rolled cigarettes was linked to the exceptionally high risk of lung cancer among Cajuns in southern Louisiana. Several new studies were begun this year overseas. Case-control studies of cancers of the esophagus, stomach, and lung and choriocarcinoma were begun in areas of China at high risk of these cancers, while a case-control study of gastric cancer was initiated in areas of Italy that are among the world's highest rates of this malignancy. Also begun was a randomized intervention trail in Linxian, China, where up to one in four persons dies of esophageal cancer, to assess the role of vitamin/mineral supplementation on reducing this extraodinarily high cancer risk. The internation studies take advantage of unique opportunities to evaluate diet and other factors, including air pollution, in the etilogy of cancer.